Benchmark: Object.create(null) vs {} unknown property

Tests:

Object.create(null);
const obj = Object.create(null); const result = []; for (i = 0; i < 100_000; i++) { result.push(obj[i]); }
{}
const obj = {}; const result = []; for (i = 0; i < 100_000; i++) { result.push(obj[i]); }
key in Object.create(null)
const obj = Object.create(null); const result = []; for (i = 0; i < 100_000; i++) { result.push(i in obj); }
key in {}
const obj = {}; const result = []; for (i = 0; i < 100_000; i++) { result.push(i in obj); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.create(null);
{}
key in Object.create(null)
key in {}

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.create(null);	406.7 Ops/sec
{}	353.6 Ops/sec
key in Object.create(null)	405.1 Ops/sec
key in {}	336.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

**What is tested:**
The provided benchmark compares the performance of three approaches:

1. `Object.create(null)`: This creates an object without any prototype chain, effectively making it a "null" object. It's used to test the performance of accessing properties on such an object.
2. `{}` (empty object literal): This creates a normal JavaScript object with no inherent properties.
3. `key in Object.create(null)` and `key in {}`: These expressions are used to test if a property exists on each of these objects.

**Options compared:**

* **Object create null vs {}**: The main difference between these two approaches is how they handle unknown (or non-existent) properties. When using `Object.create(null)`, attempting to access an unknown property throws a `TypeError`. In contrast, when using `{}`, the same property lookup will simply return `undefined`.
* **Key in Object.create(null) vs key in {}**: The main difference here is that when using `key in Object.create(null)`, it will always throw a `TypeError` if the key is unknown, whereas with `{}`, the result will be `false`.

**Pros and cons:**

* Using `Object.create(null)` has a clear security benefit, as it makes it more difficult for malicious code to access potentially sensitive properties.
* However, this approach can introduce performance overhead due to the need to check if a property exists or throw an error when accessed.
* Using `{}` is generally faster and more convenient but may expose potential vulnerabilities if not used carefully.

**Library/dependency:**
None of these benchmarks explicitly use any external libraries or dependencies. The only library being used here is `Object`, which is a built-in JavaScript object.

**Special JS feature/syntax:**
None of the test cases rely on special JavaScript features like async/await, Promises, or web workers.

**Other alternatives:**

* For testing object creation and property access performance, one might also consider benchmarking other approaches, such as using `Object.assign()` or `Object.fromEntries()`.
* If security is a top concern, additional benchmarks could focus on testing the performance of different encryption methods or secure coding practices.

In summary, this benchmark provides a useful comparison between three common approaches to handling unknown properties in JavaScript. While it's primarily focused on performance, understanding the trade-offs and implications of each approach can help developers make more informed decisions about their code.

Related benchmarks:

Object.create(null) vs {} unknown property (version: 0)

Comparing performance of: Object.create(null); vs {} vs key in Object.create(null) vs key in {}

Created: 2 years ago by: Guest

Jump to the latest result

Object.create(null);

{}

key in Object.create(null)

key in {}

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):